This invention relates to a method of oxide hardmask aluminum etching in metal dry etch processors. It consists of two steps: the step of dry etching an aluminum interconnect stack by using an etch gas composed mainly of boron trichloride/chlorine/fluoroform/nitrogen, and the step of removing etch remnants by using a vapor plasma. The function of the etch gas is to etch the aluminum interconnection pattern in the semi-conductor, and the function of the water vapor plasma is to prevent the corrosion of a chip during the process of removing etch remnants, which will further reduce water rinsing and solution cleaning as in conventional practice, of water rinsing and solution cleaning after removal of photoresist.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of processing a substrate comprising: placing a substrate having a pattern in a processing chamber, the pattern defining interconnections on the substrate; providing a plasma within the processing chamber, the plasma comprising the combination of boron trichloride, chlorine, fluoroform and nitrogen gases, using the plasma to etch a film exposed on the substrate; removing the substrate from the processing chamber; placing the substrate in a second chamber; and processing the substrate in the second chamber under process conditions comprising; a first step that provides processing at conditions comprising: a pressure of about 7000 milliTorr (mT) to about 9000 mT; oxygen gas levels from about 1500 to about 3000 standard cubic centimeters (sccm); and water vapor levels from about 1000 to about 2000 sccm; a second step that provides processing at conditions comprising: a pressure of about 2000 milliTorr (mT) to about 4000 mT; and water vapor levels from about 1000 to about 2000 sccm; and a third passivation step that provides processing at conditions comprising: a pressure of about 2000 milliTorr (mT) to about 4000 mT; a plasma-comprising: a level of power about 2000 watts from one of an inductive source and a microwave source capable of producing an amount of chemical disassociation; oxygen gas levels from about 1500 to about 3000 standard cubic centimeters (sccm); and water vapor levels from about 1000 to about 2500 sccm.
2. The method of claim 1 wherein said etching of the film includes a breakthrough step, a first main etch step, a second main etch step and an over etch step.
3. The method of claim 2 wherein the breakthrough step provides processing at conditions comprising: a pressure of about 6 milliTorr (mT) to about 15 mT; a plasma comprising: a level of radio-frequency (RF) power from about 400 watts to about 1000 watts from an inductive source capable of producing an amount of chemical disassociation; a level of bias voltage from about 100 to about 200 volts; excited species of gasses derived from chlorine gas levels from about 80 to about 150 standard cubic centimeters (sccm); boron trichloride gas levels from about 80 to about 150 s.c.c.m.; nitrogen gas levels from about 5 to about 15 s.c.c.m.; fluoroform gas levels from about 5 to about 15 s.c.c.m.
4. The method of claim 2 wherein the first main etch step provides processing at conditions comprising: a pressure of about 6 milliTorr (mT) to about 15 mT; a plasma comprising: a level of radio-frequency (RF) power from about 400 watts to about 1000 watts from an inductive source capable of producing an amount of chemical disassociation; a level of bias voltage from about 100 to about 200 volts; excited species of gasses derived from chlorine gas levels from about 50 to about 150 standard cubic centimeters (sccm); boron trichloride: gas levels from about 50 to about 150 s.c.c.m.; nitrogen gas levels from about 5 to about 15 s.c.c.m.; fluoroform gas levels from about 5 to about 15 s.c.c.m.; for a time to be determined by the thickness of the film exposed on the substrate.
5. The method of claim 2 wherein the second main etch step provides processing at conditions comprising: a pressure of about 6 milliTorr (mT) to about 15 mT; a plasma-comprising: a level of radio-frequency (RF) power from about 400 watts to about 1000 watts from an inductive source capable of producing an amount of chemical disassociation; a level of bias voltage from about 100 to about 200 volts; excited species of gasses derived from chlorine gas levels from about 50 to about 150 standard cubic centimeters (sccm); boron trichloride gas levels from about 50 to about 150 sccm.; nitrogen gas levels from about 5 to about 15 sccm.; fluoroform gas levels from about 5 to about 15 sccm.; for a time to be determined by the amount of microloading.
6. The method of claim 2 wherein the overetchstep provides processing at conditions comprising: a pressure of about 6 milliTorr (mT) to about 15 mT; a plasma-comprising: a level of radio-frequency (RE) power from about 400 watts to about 1000 watts from an inductive source capable of producing an amount of chemical disassociation; a level of bias voltage from about 100 to about 200 volts; excited species of gasses derived from; chlorine gas levels from about 50 to about 150 standard cubic centimeters (sccm); boron trichloride gas levels from about 50 to about 150 sccm.; nitrogen gas levels from about 5 to about 15 sccm; fluoroform gas levels from about 5 to about 15 sccm.; for a time to be determined by an etch rate.
7. The method of claim 1 wherein the pattern is defined on the substrate by one of a hardmask and mask.
8. The method of claim 1 , wherein the interconnections on the substrate is one of aluminum, aluminum copper alloy, copper, and titanium.
9. The method of claim 1 , wherein the material exposed on the substrate in the processing chamber is one of siliconoxynitride, silicon dioxide, titanium nitride, titanium, aluminum, aluminum copper alloy, and copper.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 6, 2002
July 26, 2005
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